Shutterstock's alexa rank is 194 and it says it has over 35 million images. Article says 1581 and 35 million
Dreamstime's rank is 651 and just crossed 23 million images. Article says 1066 and 22 million
I don't know when DT's rank was ever lower than SS, so perhaps the article is based on ranks other than global or is just wrong. As far as earnings, I'm assuming that's just one person's results, so it's largely meaningless for everyone else.